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The present invention relates to wall mountable, electrically activated, fumigation devices that are suitable for use with electric sockets having varied alignments relative to the wall.
Device are known for fumigating an enclosed area, such as a room of a house, by expelling a fumigant (e.g. typically an insecticide or fragrance) upon an application of heat. As disclosed in U.S. Pat. No. 5,796,914, some of these devices include a canister containing the fumigant, and an electric heater positioned adjacent the fumigant. When activated, the device produces a fog that is expelled out to fumigate the room.
Before the application of heat the fumigant is typically in solid form. It subsequently transforms into a slightly flowable gel material in response to the initial introduction of heat. Further heating will produce the fog. During the gel phase there is thus a spilling potential if the outlet of the device is pointed downwardly and no other structures are provided to avoid the problem.
Complicating matters, on a vertical wall blade sockets are typically either side by side, or alternatively one over the other. One previous fumigation device, U.S. Pat. No. 2,714,749, included a horizontally disposed vaporizer whose horizontally extending heater was inserted into the fumigant. There was an outer housing which retained the fumigant until it was dispensed. The housing was rotatable around the heater to orient a retaining cavity portion of the housing in a downward position and an outlet portion of the housing in an upward position, regardless of wall electrical outlet configuration.
Other approaches for avoiding the theoretical spill problem relied on using fumigants which did not have to go through a flow state during heating. For example, there have been numerous systems where a pad is impregnated with fumigant, and then later heated to directly release the vapors. See e.g. U.S. Pat. Nos. 4,214,146; 4,391,781; and 6,044,202. Unfortunately, there are applications where the use of flowable type fumigants is preferred.
U.S. Pat. No. 5,796,914 tried an improved approach of using a flowable type fumigant, albeit with spill protection. It provided a plug mounted on an angle with respect to the housing, thus allowing the mouth to be positioned at least somewhat upwardly regardless of the orientation of the electrical outlet. A potential disadvantage of this device was that the orientation of the mouth of the canister was fixed at an angle with respect to the electrical plugs, so that the level of fumigant in the canister was limited to some extent.
As such, a need still exists for electrical fumigators that dispense preferred foggers while providing flexibility in mounting.
In one aspect the invention provides an electric fumigation device. There is a housing including a delivery port positioned essentially along a longitudinal axis of the housing, and a storage cavity located within the housing having an outlet in communication with the housing delivery port, the cavity containing a heat-activatable fumigant.
There is also a heater assembly having an electrical plug extending outwardly from an end of the housing opposite the delivery port (the plug being configured to be received by an electrical outlet), and a heater extending between outer radial walls of the housing. The heating device is in electrical communication with the electrical plug and in thermal communication with the fumigant in the cavity. There is also a trap a formed outside the cavity between the housing and heater, the trap being in part between the outlet and the delivery port.
In preferred forms, the heater extends essentially horizontally between outer radial walls of the housing along the longitudinal axis of the housing, the delivery port has a horizontally extending aperture downstream of the cavity, and either the heater extends into the cavity, or the heater is disposed entirely outside the cavity. If desired, the housing and/or heater can be essentially ball-shaped.
In another aspect the invention provides a method of fumigating an area in which an electrical receptacle is mounted on a wall with a fumigant. One provides an electrically activatable device of the above kind. One then plugs the fumigating device into the electrical receptacle and allows electricity from the electrical receptacle to cause a release of the fumigant.
The present invention achieves mounting flexibility for allowing the device to be received by an electrical receptacle on a vertical wall in any angular orientation, without sacrificing heat performance, or increasing spill potential. Because the delivery port is along the longitudinal axis of the housing, it is never pointed downward. Further, the fumigant is similarly arrayed relative to the heater regardless of how the device is plugged in.
The trap prevents the spillage of liquified fumigant from the device. Furthermore, the delivery port directs fumigant vapors away from the wall and into the interior of a room to be fumigated. This not only assists in distribution of the vapors, it also protects wall treatments and/or minimizes the need to clean the wall around the device.
Placing the heater between housing outer radial walls insures better thermal transfer. It also permits a compact design.
The foregoing and other advantages of the invention will appear from the following description. In the description, reference is made to the accompanying drawings which form a part thereof, and in which there is shown by way of illustration, and not limitation, preferred embodiments of the invention. Such embodiments do not necessarily represent the full scope of the invention. Reference must therefore be made to the claims herein for interpreting the scope of the invention.